Human interleukin-4 (IL-4) was first cloned and characterized by Yokota et al., Proc. Natl. Acad. Sci., Vol. 83, pgs. 5894-5898 (1986). IL-4 is a highly pleiotropic lymphokine which affects many different components of the immune system. It has T cell growth factor (TCGF) activity; and B cell growth factor activity. It is capable of potentiating the TCGF activity of interleukin-2 (IL-2) and the colony forming activity of granulocyte-macrophage colony stimulating factor. It induces the preferential production of IgG.sub.1 and IgE, and induces the expression of human leukocyte class II DR antigens. These activities suggest several possible therapeutic uses, e.g. as a potentiating agent for IL-2 anticancer therapy, as a potentiating agent for GM-CSF stimulated bone marrow regeneration, or as an agent to treat bare lymphocyte syndrome, Touraine, Lancet, pgs. 319-321 (Feb. 7, 1981); Touraine and Betuel, Human Immunology, Vol. 2, pgs. 147-153 (1981); and Sullivan et al., J. Clin. Invest., Vol. 76, pgs. 75-79 (1985).
An important aspect of any therapy involving drugs is the ability to predict and/or monitor concentration levels in the blood or other patient body fluids. Monoclonal antibodies are widely used for this purpose, e.g. Springer, ed., Hybridoma Technology in the Biosciences and Medicine (Plenum Press, N.Y., 1985); and U.S. Pat. Nos. 4,562,003; 4,486,530; and 4,255,329.
In the production of genetically engineered proteins such as IL-4, separation of the expressed protein from the transformed host cells and/or their culture supernatants is a major problem. Frequently separation procedures involve one or more passes of crude material through immunoadsorbent columns. Monoclonal antibodies specific for the protein to be purified are crucial elements of such columns. Such monoclonal antibodies can also be used to measure the degree of purification achieved by a particular protocol, e.g. by "Western" blot analysis, Burnette, Anal. Biochem., Vol. 112, pgs. 195-203 (1981).
From the foregoing it is evident that the availability of monoclonal and/or polyclonal antibodies specific for IL-4 could facilitate medical and veterinary applications of the compound by improving current methods of purification, and by providing means for monitoring concentrations of IL-4 in body fluids, such as blood, urine, or the like.